Question: seperating convexhull

Dear all! I have 2 different lists:

ch1 := [[0.1e-1, -.56], [0.25e-1, -.57], [0.35e-1, -.555], [.115, -.43], [.16, -.3], [.195, -.24], [.28, -.155], [.315, -0.25e-1], [.32, -0.85e-1], [.41, .19], [.425, .11], [.425, .425], [.425, .43], [.425, .44], [.43, .12], [.43, .265], [.43, .405], [.43, .445], [.435, .295], [.435, .38], [.465, .44], [.5, .29], [.505, .31], [.505, .395], [.51, .37]];

ch2 := [[0.3e-1, -.5], [0.5e-1, .575], [.11, .495], [.15, -.295], [.19, -.33], [.23, -.155], [.23, .475], [.255, .55], [.265, -.205], [.27, .465], [.3, -0.25e-1], [.305, -0.15e-1], [.31, .54], [.32, 0.15e-1], [.325, .445], [.335, -0.85e-1], [.335, .44], [.365, .115], [.38, -0.5e-2], [.405, .36], [.41, 0.5e-1], [.485, .2], [.5, .235], [.505, .465], [.51, .46], [.525, .305]]; 

I can pointplot them. Now, I want to connect the points together in each case. I use

ch11 := simplex[convexhull](ch1,output=[hull]);

plot(ch11): 

ch22 := simplex[convexhull](ch2,output=[hull]);

plot(ch22): 

For ch1 if someone uses pointplot will find a curve. I just want connect these points together. But when I look at the ch11 I see many of points where I want to joint them together have omitted. Also I want to find a continious curve where starts from [0.25e-1, -.57] and end to [0.1e-1, -.56]. But in ch11 the order of list has changed.

In case of ch2 with pointplot one finds two parallel curves(not exactly). Now I want to connect these points as two continious parallel curves. But maple give me only one curve. Waht should I do in both cases? Thanks a lot.